It has been the practice in the past to provide apparatus to form a sleeve of thermoplastic material on a series of rotatable sleeve-forming mandrels that are carried on a circular turret, for example, as shown in U.S. Pat. No. 3,802,942 issued Apr. 9, 1974. This patent discloses the process of forming sleeves from the point where a foamed material is extruded as a tube, then slit into a flat sheet. The sheet is provided with a stretch orientation in the direction of its width by reason of its being inflated as it is extruded in tube form. The inflation of the tube stretches the tube in a circumferential direction and this provides the built-in shrinkage characteristic which is desired. Thus, when the material is formed into a cylinder with the direction of shrink extending circumferentially about the cylinder and this cylinder or sleeve is then applied to the container, heating of the sleeve will shrink the sleeve into conformity to the external surface of the container.
The method and apparatus for producing the shrink sleeves used in the present invention is essentially the same as that disclosed in the above-referred-to U.S. Pat. No. 3,802,942, and reference to such patent may be had and the disclosure of this patent is incorporated herein by reference. FIGS. 1 and 2 of this patent show two essentially similar systems, in plan view, wherein sleeving material 15a is brought into association with preheated containers at the turret 58. At turret 58 the material is formed on mandrels into sleeves and then put onto glass containers, and the containers with the sleeves thereon exit from the mandrel and pass through a heat-shrink oven 77 on their way to an exit conveyor 81. The newly formed or preheated containers are picked up at the end of a feed screw 53 in both FIG. 1 and FIG. 2 embodiments of this patent. It should be pointed out that in this patent the containers, at the point of pickup and throughout their entire travel through the ovens and the sleeving operation, are carried by an individual set of tongs carried on an endless chain-drive system. There are as many tongs as there are positions along the length of the chain used to convey the bottles. The bottles are spaced apart a fixed distance, depending on the spacing of the tongs. Thus, the above-referred-to patent discloses an endless pair of chains, carrying a series of neck-grasping chucks for holding the necks of the containers through the cycle of operation of preheating the containers, applying a shrinkable sleeve to the container and subsequently heat-shrinking the sleeve that has been applied to the container. It will be noted that in this patent the shrinking of the sleeve takes place in a long straight line moving away from the turret where the sleeves have been formed and applied to the container. This patent also provides a clear teaching of a bottle-handling system where a relatively tall set of tong-transporting mechanisms are used to pick up the containers, on the fly, and drop the containers, on the fly, with the tong mechanism having the ability to be raised and lowered and opened and closed while moving in the straight line motions.